Considering moving all Launchpad branches to 2a - based formats

[Gary Poster]

Sounds good.  The only thing I can think of to be especially careful of is sourcecode branches.  Hiccups there can affect ec2, buildbot, and production.  The only thing I can think of happening is just some slow branch updates until we migrate the local branches, so no really big deal.  (I have a vague memory of other pain from changes like this back in Foundations days, but nothing helpful.)

Gary